RV/Boat Outlet GFCI?

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ddecart

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A friend was telling me about the new cottage-on-a-lake that he recently purchased, and how it has power down at the dock where he's hoping to hook up his boat. Looks like about 100' or so from the house to the water.

From his description, it sounds like he's got a NEMA TT-30R on some sort of panel out there, but he doesn't think it's GFCI protected.
Is there any reason that 30 amp receptacle should NOT have a GFCI on it? The boat will plug into it, and the boat has its own GFCI outlets.



Thanks,
Dave
 
ddecart said:
A friend was telling me about the new cottage-on-a-lake that he recently purchased, and how it has power down at the dock where he's hoping to hook up his boat. Looks like about 100' or so from the house to the water.

From his description, it sounds like he's got a NEMA TT-30R on some sort of panel out there, but he doesn't think it's GFCI protected.
Is there any reason that 30 amp receptacle should NOT have a GFCI on it? The boat will plug into it, and the boat has its own GFCI outlets.



Thanks,
Dave
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I sure would like to see it GFCI protected, but so far I can't find a code section to cite as a violation if it isn't protected.
 
GFCI not required.

My understanding is that if the power goes out the bilge pump etc. will not work and you end up with a sunken boat at the dock.
With that being said, we will often install the circuit on a GFCI in residential settings that have someone living at or near the dock, so power can be monitored.

At a lake house I'd be inclined to leave the GFCI out of the circuit.
 
There will be at least one battery-powered bilge pump, which can run continuously for a day or two without shore power before depleting the battery. And if your bilge pump is running continuously, you have bigger problems.

While there might not be any mandate, I can't think of a good reason not to equip it with a GFCI.
 
ddecart said:
NEMA TT-30R
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Shore power receptacles are required to be locking. I do not believe this configuration is. Also 2017 now includes residential dock in the scope of 555 and therefore GFCI protection for equipment at 30 mA is a requirement on the feeder to be compliant with the current version in addition to many other requirements that previously were not enforceable by this section. I do not have a copy yet to paste a reference someone here can probably pull it up and provide.
 
oldsparky52 said:
To me it does not matter if it's required or not, I would have it on a GFCI.
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As much as I agree with this whole heartedly, many boats are so leaky out of manufacturing line in terms of current that it is not possible to put them on a 5 mA GFCI circuit. 30mA is proving tough in our area. Boat manufactures need to get on page.
 
My bigger concern is voltage rise on the EGC, which a GFCI will not protect you from. There needs to be better isolation around docks and other powered structures in the water, but that compromises what we are trying to do with low impedance for fault clearing purposes. Swimming pools is practical to create equipotential bonding, but this is not practical on a lake, river, ocean. So far the best thing is to at least prohibit swimming near anything that is connected to the electrical grid. Something that is self powered, even if a isolated source on the shore but not tied to the grid in any way, isn't going to have any influence from unrelated equipment that it happens to have a connection to via grounded/grounding conductors.
 
luckylerado said:
Shore power receptacles are required to be locking. I do not believe this configuration is. Also 2017 now includes residential dock in the scope of 555 and therefore GFCI protection for equipment at 30 mA is a requirement on the feeder to be compliant with the current version in addition to many other requirements that previously were not enforceable by this section. I do not have a copy yet to paste a reference someone here can probably pull it up and provide.
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Thanks. The description was some handwaving, and what he described sounded like a TT-30R, though it may be a conventional shore power there as well. Power was present down to the shore, but he added the dock, so who know what someone may have put in. Regardless, it sounds like GFCI protection is newly required.



The boat sits there without shore power right now, so I'm assuming he doesn't NEED power for the bilge pump.



Sounds like a little more investigation is in order to determine what he has there, and that there may be inherent difficulties with a GCFI connection to a boat.
 
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ddecart said:
Thanks. The description was some handwaving, and what he described sounded like a TT-30R, though it may be a conventional shore power there as well. Power was present down to the shore, but he added the dock, so who know what someone may have put in. Regardless, it sounds like GFCI protection is newly required.
The boat sits there without shore power right now, so I'm assuming he doesn't NEED power for the bilge pump.
Sounds like a little more investigation is in order to determine what he has there, and that there may be inherent difficulties with a GCFI connection to a boat.
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Some Marine Engineers' configurations differ from what we're accustomed to in terms of dealing with ground fault anomalies on brick and stick (domicile) situations.


Multi-million dollar luxury yachts, although require 24/7 lookout for potential power failure caused by ground fault is common but it is not always the case in some smaller water craft, though these smaller ones can be really expensive too.



The Marine Engineer who designed the craft is faced with an important decision to make--whether the bilge pump power should be kept on or run the risk of sinking the unattended boat should the GFCI is tripped.



One solution I've seen is having an independent circuit feeding the bilge pump (sans GFCI) much like fire protection systems in high occupancy structures. This doesn't take into account the GFCI that comes with POCO if ever there is one.


This logic may or may not apply to RVs given the fact that RVs don't have bilge pumps.


RV owners can make the decision whatever makes them have a good night's sleep.
 
Here's a bit of information. Some boats have "reverse polarity" indicator lights. How is that wired? I believe the light connects between the neutral conductor and the ground conductor.

Guess what that's called, a ground fault. :)

The resistance is usually high enough that it won't trip a GFCI, but ......
 
oldsparky52 said:
Here's a bit of information. Some boats have "reverse polarity" indicator lights. How is that wired? I believe the light connects between the neutral conductor and the ground conductor.

Guess what that's called, a ground fault. :)

The resistance is usually high enough that it won't trip a GFCI, but ......
Click to expand...

Same thing happens with plug in "bug eye" testers, or even some automated switching devices like timers, occupancy sensors that don't have a neutral lead.
 
Thanks for the continued education, guy.

Talked to him again yesterday, with pics as reference. Shore power outlet? Nope. TT30? Nope. Not sure what's out there.

His primary concern is keeping his 6 on board batteries charged. Running the A/C would be a bonus. Looks like a proper install of a circuit to match his boat's draw is in order,either way.
 
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